Spring使用@Autowired不能注入BlockingQueue的问题

 

今天遇到一个问题，使用spring4配置BlockingQueue，在Java代码里面使用@Autowired注释方式注入该BlockingQueue，一直报错。

我的代码如下：

    @Autowired
    private BlockingQueue<CoreTask> alarmInnerQueue;

 

我的XML如下：

<bean id="alarmInnerQueue" class="org.kanpiaoxue.test.concurrent.UniqueLinkedBlockingQueue"/>

 说明一下，UniqueLinkedBlockingQueue 这个类是BlockingQueue的一个实现，我自己写的。

报错如下：

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.util.concurrent.BlockingQueue com.baidu.rigel.dmap.sf.service.impl.AlarmFailureServiceImplTest.alarmInnerQueue; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.util.HashMap$Values' to required type 'java.util.concurrent.BlockingQueue'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.util.HashMap$Values] to required type [java.util.concurrent.BlockingQueue]: no matching editors or conversion strategy found
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:555)
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
	... 26 more
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.util.HashMap$Values' to required type 'java.util.concurrent.BlockingQueue'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.util.HashMap$Values] to required type [java.util.concurrent.BlockingQueue]: no matching editors or conversion strategy found
	at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:74)
	at org.springframework.beans.TypeConverterSupport.convertIfNecessary(TypeConverterSupport.java:40)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1014)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:527)
	... 28 more
Caused by: java.lang.IllegalStateException: Cannot convert value of type [java.util.HashMap$Values] to required type [java.util.concurrent.BlockingQueue]: no matching editors or conversion strategy found
	at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:287)
	at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:107)
	at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:64)
	... 32 more

 最后在spring的网站发现这是一个Bug，到现在还没有修复。而是采用了配置

javax.annotation.Resource的方式来绕过这个BUG。

正确的代码如下：

    @Resource(name="alarmInnerQueue")
    private BlockingQueue<CoreTask> alarmInnerQueue;

 

 

网站地址：https://jira.spring.io/browse/SPR-7798

http://forum.spring.io/forum/spring-projects/container/64548-problem-injecting-blockingqueue-by-applicationcontext-xml

内容：

Details

• Type: Bug
• Status:RESOLVED
• Priority: Minor
• Resolution:Duplicate
• Affects Version/s:3.0.5
• Fix Version/s:None
• Component/s:Core:AOP
• Labels:

  None

• Reference URL:

  http://forum.springsource.org/showthread.php?t=72474
• Last commented by a User:

  true

Description

Cannot @Autowire to inject an instance of java.util.concurrent.BlockingQueue. The above forum has a post from 2009. I was able to reproduce this problem and have attached a minimal example. This works with XML based bean configuration but not with the annotation @Autowired.

AppComponent.java:

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package com.example;   import java.util.concurrent.BlockingQueue;   import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.stereotype.Component;   @Component public class AppComponent {       @Autowired     public BlockingQueue queue;       public static void main(String[] args) {           new ClassPathXmlApplicationContext("com/example/context.xml").getBean(AppComponent.class);     } }

Config.java:

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package com.example;   import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue;   import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;   @Configuration public class Config {       @Bean     public BlockingQueue blockingQueue() {         return new LinkedBlockingQueue();     } }

context.xml:

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<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"     xmlns:context="http://www.springframework.org/schema/context"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd ">     <context:component-scan base-package="com.example" /> </beans>

The runtime error is:

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Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'appComponent': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public java.util.concurrent.BlockingQueue com.example.AppComponent.queue; nested exception is org.springframework.beans.FatalBeanException: No element type declared for collection [java.util.concurrent.BlockingQueue]     at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1074)     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)     at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)     at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)     at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)     at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)     at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)     at com.example.AppComponent.main(AppComponent.java:17) Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: public java.util.concurrent.BlockingQueue com.example.AppComponent.queue; nested exception is org.springframework.beans.FatalBeanException: No element type declared for collection [java.util.concurrent.BlockingQueue]     at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:502)     at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84)     at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:282)     ... 13 more Caused by: org.springframework.beans.FatalBeanException: No element type declared for collection [java.util.concurrent.BlockingQueue]     at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:740)     at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:703)     at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:474)     ... 15 more

Attachments

1. 

   inject-blocking.zip

   07/Dec/10 10:35 AM

   3.54 MB

Issue Links

is superseded by

 SPR-8519 Support injection of collection-typed beans using @Autowired+@Qualifier or @Inject+@Named

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Michael F added a comment - 05/Jul/11 7:13 AM

(I posted the same response in the forum thread linked above.)

If you want auto-wire the Queue try to use JSR-250's @Resource annotation and a reasonable qualifier. Spring supports these annotations and should correctly inject the queue.)

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@Component public class B {   @Resource(name="myBlockingQueue")   private BlockingQueue<Integer> blockingQueue; }

@Autowired and @Resource behave differently.

Background info can be found in the documentation: Fine-tuning annotation-based autowiring with qualifiers

 

Chris Beams added a comment - 07/Jul/11 6:51 PM

Please see SPR-8519, which aims to address this and a number of other similar issues related to collection autowiring.

 

Marty Kube added a comment - 10/Jul/11 6:16 PM

Great, thanks. @Resource solved the issue.